Fix zone in which temp-zone parsed data is allocated for the function scope on the boundary.

src/parsing/parser-base.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PARSING_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
@@ skipping 689 matching lines @@
   Scope* NewScopeWithParent(Scope* parent, ScopeType scope_type) const {
     // Must always use the specific constructors for the blacklisted scope
     // types.
     DCHECK_NE(FUNCTION_SCOPE, scope_type);
     DCHECK_NE(SCRIPT_SCOPE, scope_type);
     DCHECK_NE(MODULE_SCOPE, scope_type);
     DCHECK_NOT_NULL(parent);
     return new (zone()) Scope(zone(), parent, scope_type);
   }
 
-  DeclarationScope* NewFunctionScope(FunctionKind kind) const {
+  // Creates a function scope that always allocates in zone(). The function
+  // scope itself is either allocated in zone() or in target_zone if one is
+  // passed in.
+  DeclarationScope* NewFunctionScope(FunctionKind kind,
+                                     Zone* target_zone = nullptr) const {
     DCHECK(ast_value_factory());
-    DeclarationScope* result =
-        new (zone()) DeclarationScope(zone(), scope(), FUNCTION_SCOPE, kind);
+    if (target_zone == nullptr) target_zone = zone();
+    DeclarationScope* result = new (target_zone)
+        DeclarationScope(zone(), scope(), FUNCTION_SCOPE, kind);
     // TODO(verwaest): Move into the DeclarationScope constructor.
     if (!IsArrowFunction(kind)) {
       result->DeclareDefaultFunctionVariables(ast_value_factory());
     }
     return result;
   }
 
   V8_INLINE DeclarationScope* GetDeclarationScope() const {
     return scope()->GetDeclarationScope();
   }
@@ skipping 4733 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H